1. Field of the Invention
The invention relates to a device for directing light reflected from an object in a scene through at least one lens and into a camera.
2. Background of the Invention
There are several methods known as biometrics for recognizing or identifying an individual. These methods include analyzing a signature, obtaining and analyzing an image of a fingerprint and imaging and analyzing the retinal vascular patterns of a human eye. Recently the art has used the iris of the eye which contains a highly detailed pattern that is unique for each individual and stable over many years as a non-contact, non-obtrusive biometric. This technique is described in U.S. Pat. No. 4,641,349 to Flom et al. and U.S. Pat. No. 5,291,560 to Daugman. The systems described in these references require the person being identified to hold at least one of their eyes in a fixed position with respect to an imaging camera which takes a picture of the iris. While this procedure is satisfactory for some applications, it is not satisfactory for quick transactional activities such as using an automated teller machine, access control or automated dispensing.
The iris identification techniques disclosed by Flom and Daugman require a clear, well-focused image of the iris portion of the eye. In a present commercial embodiment an image is obtained and an iris code is derived from the image. That code is stored in an image file for a particular individual thereby completing an enrollment process. When that person asks to be identified a new image is used to compute the iris code which is then compared with the iris code on file. In this way the person can be identified quite rapidly. However, prior to the present invention there has not been an optical system which could rapidly acquire a sufficiently clear image of an iris of the person to be identified unless that person positioned his eye in a fixed position relatively close to an imaging camera. There is a need for an optical system which will rapidly obtain a clear picture of the iris of a person standing remotely from the optical system and in an uncertain position. This system would be particularly useful to identify users of automated teller machines as well as individuals seeking access to a restricted area or facility or other applications requiring user identification.
Automated teller machines, often called ATMs, are compact, sophisticated electrical devices which have a large number of electrical and electromechanical subsystems arranged in a restricted volume. However, there are small spaces immediately behind the cover plates of the automated teller machine or around the bezel of the display in which a very compact optical system could be placed. The location and size of that space may differ among automated teller machines. Yet, there are several manufacturers of these machines, two of which are NCR and OKI Electric. Each manufacturer offers several models, but the products in each manufacturer's ATM product line are quite similar. Although there are several basic types of ATMs, the NCR machine and the OKI machine are representative. Any optical system for iris identification of ATM users should be suitable for use in the various types of ATM machines. The system must also be able to rapidly obtain a clear image of the iris of the person using the automated teller machine and direct it to a camera. The camera records the image and transmits that image to a digital processor. The processor compares the iris code of the user's image with a file copy of the iris code defined by an enrollment process to complete the identification.
Many automated teller machines and similar financial transaction machines are equipped with video cameras typically positioned above the display panel. These video cameras are used for security purposes and are positioned to take a picture of the head and shoulders of the person using the machine. These cameras are not equipped to rapidly focus on a small region of the user's face. It is not possible for these cameras to obtain a sufficiently detailed image of the iris of the user of the machine which iris image could be used to identify the user. Therefore, there is a need for an optical system which can rapidly acquire and provide a clear, detailed image of the iris of the user which image is sufficient for identification of the user based upon iris analysis. Preferably, at least one of the cameras used with this optical system could be used as a conventional security camera.